timolins/react-hot-toast ? reverse-engineered prompt

Build me a lightweight React toast notifications library that feels polished and easy to use.

I want an API where I can call something like a toast function from anywhere in my app and render a single toaster component near the root. It should support basic success, error, loading, and custom messages, plus a promise based flow so a loading toast can automatically turn into success or error when the promise finishes. Make it customizable, accessible, and nice looking by default, but also flexible enough that people can style their own notifications.

Please include a small demo or docs site showing how to install it and use it in a simple app. Keep it fast and tiny, and make sure the notifications can stack, dismiss, and be controlled cleanly. If you need to check current React best practices or docs online, go ahead.